Method for producing detergent cakes

ABSTRACT

An improved process for the production of detergent cakes containing a monoalkylsulfosuccinate wherein the detergent is produced in the presence of water representing between 10 and 20% by weight of the material.

' United States Patent Perla et al.

[ Dec. 16, 1975 METHOD FOR PRODUCING DETERGENT CAKES Inventors: Giulio Perla, Rome; Giuseppe Mattiello, Nettuno, both of Italy Assignee: Colgate-Palmolive Company, New

York, NY.

Filed: July 9, 1973 Appl. No.: 377,676

Related US. Application Data Continuation of Ser. No. 204,297, Dec. 2, 1971, abandoned.

Foreign Application Priority Data Dec. 7, 1970 Italy ..55234/70 us. c1.. 252/557; 252/174; 252/DIG. 16 11 1. (:1. ..c111) 1 12; 0111) 11/04; I 4 c1113 17/00 Field 61 Search 252/121, 134, 174, 367, 252/368, 557, DIG. 16

References Cited UNITED STATES PATENTS 8/1946 Bodman 252/121 6/1965 Sweeney 252/552 4/1966 Hendricks... 252/117 3,594,323 7/1971 Taylor 252/545 X 3,640,882 2/1972 Groves 252/121 FOREIGN PATENTS OR APPLICATIONS 798,803 11/1968 Canada 252/557 646,347 8/1962 Canada 252/121 1,059,089 2/1967 United Kingdom 252/DIG. 16 550,757 1/1904 United Kingdom 252/121 Primary Examiner-Dennis E. Talbert, Jr. Assistant ExaminerDennis L. Albrecht Attorney, Agent, or Firm-Kenneth A. Koch, Esq.; Herbert S. Sylvester, Esq.; Murray M. Grill, Esq.

[57] ABSTRACT An improved process for the production of detergent cakes containing a monoalkylsulfosuccinate wherein the detergent is produced in the presence of water representing between 10 and 20% by weight of the material.

5 Claims, N0 Drawings METHOD FOR PRODUCING DETERGENT CAKES This is a continuation, of application Ser. No. 204,297 filed Dec. 2, 1971, now abandoned.

The process of this invention enables the production of superior cakes in a simple, economical, and facile manner whereby such detergent cakes may be formed in the equipment normally used and present in any soap making operation, even those operations where modern processing equipment is not available. Accordingly, the capital equipment cost for converting in accordance with this invention a soap bar production facility to a detergent bar production facility is negligible or nonexistent. The raw materials required for the production of detergent cakes by the process of this invention are readily available and inexpensive. The detergent cakes formed by the process of this invention are of an exceptionally high quality, and provide a quick and desirable amount of foam. The detergent cake both wet and dry has substantially the same tactile characteristics and density as a normal soap bar, and the detergent cake, when used in a body of hard water, results in a complete absence of any objectionable adherent, scum or curd such as that which clings to the sides of a bathtub and forms a ring thereon, but the detergent confers a translucence to water of the type formed by soap thereby making it readily evident that the water has been used. In addition, the detergent cakes of this invention can be free or substantially free from inorganic salts and therefore do not feed gritty and are devoid of undesirable efflorescence.

It is an object of this invention to provide a novel method for the manufacture of a cleansing cake containing a monoalkyl sulfosuccinate, using a controlled amount of water. By using from to by weight of water during the sulfonation stage, the viscosity of the sulfonation reaction mass is substantially decreased from the viscosity of this mass in the presence of smaller amounts of water, i.e., less than 10% by weight. This decrease in viscosity resulted in a higher yield of active ingredient in a shorter time period that for monoalkylsulfosuccinate detergents prepared in the presence of a smaller quantity of water. Other advantages of the method over the dry process are that the odor of the detergent bar is better and the operation is less critical i.e., there is a lesser likelihood of obtaining hard grains in the final product. A good bar texture is more reliable obtained, and the detergent bars themselves are much more homogeneous.

In accordance with the invention, a solid detergent bar is formed by a process including the steps of reacting a monoalkyl ester of a cis or transbutenedioic acid with a sulfite at an elevated temperature and in the presence of from 10 to 20% by weight of water and a molten plasticizer of the type specifically set forth hereinbelow, cooling the mass to thereby form a product containing a substantially neutral water soluble salt of a sulfosuccinate monoester of the type described in detail hereinbelow in admixture with the plasticizer, drying the product, and then processing the solid on conventional soap processing equipment thereby to form the product into cake or bar form.

The monoalkyl sulfosuccinates useful in the present invention are desirably formed by the reaction of a higher molecular weight alcohol with a cis or transbutenedioic acid or maleic anhydride. The high molecular weight alcohol is preferably lauryl alcohol or a mixture of alcohols in which lauryl alcohol predominates. Preferably, the lauryl alcohol is reacted with maleic anhydride to form the monolauryl ester of maleic acid. The lauryl maleate is then reacted with a sulfite such as sodium sulfite to produce disodium lauryl sulfosuccinate. The reaction between the lauryl maleate and the sodium sulfite is preferably carried out with the law ryl maleate dissolved or dispersed in a mixture of a molten plasticizer such as glyceryl monostearate and water, although the plasticizer may be added subsequent to the reaction.

The product of the reaction along with the plasticizer is capable of being used as such or with additives such as perfumes, opacifiers, and the like for forming detergent bars.

It will be appreciated that these relatively inexpensive, easily obtainable materials can be reacted in readily available equipment as unsophisticated as a kettle, yet form a highly desirable product. Thus, maleic anhydride is simply reacted with a suitable alcohol to provide the ester, the latter is then diluted with the plasticizer and water, and then the maleic acid monoester is reacted'with the sulfite to produce the corresponding sulfosuccinate monoester which is substituted according to the sulfite used. Thus, for example, disodium alkyl sulfosuccinate is produced when sodium sulfite is used. In place of the sodium sulfite there may desirably be used other alkali metal or ammonium sulfites, or alkaline earth metal sulfites, and bisulfites.

While lauryl'alcohol and mixtures of alcohols containing lauryl alcohol (as derived from petrochemicals, coconut oil, or palm kernel oil, hydrogenated if desired) are preferred, it is possible to use reactants containing an acyclic radical having twelve carbon atoms and a suitable moiety which will link such acyclic radical to the butenedioic acid, such as for example lauric monoethanolamide or lauric diethanolamide. The acyclic chain of the said reactant may be comprised solely of twelve carbon atoms, or the reactant used may comprise mixtures in which the size of the acyclic chain varies from 12 to 18 carbon atoms. In such mixtures, however, a predominant portion of the acyclic chains must have twelve carbon atoms. By predominant portion it is meant that at least twenty percent and preferably fifty percent of the acyclic chains contain twelve carbon atoms. The compound used, however, must have a reactive hydroxyl group.

The monoalkyl sulfosuccinate (as used herein the term monoalkyl" refers to radicals formed from alcohols and hydroxyl bearing equivalents thereof as described in the paragraph immediately above) should be present in an amount of about 40 to 95 percent by weight of the detergent bar mass; i.e., before the addition of nonessential additives such as perfume, color, etc. Preferably, the half ester is present in an amount of between about 60 and percent by weight.

The plasticizing agent, which advantageously will also be used, in conjunction with the water, as a reaction medium for the reacting constituents, is desirably a waxy or wax-like material such as a glyceryl monoester, and is preferably glyceryl monostearate. (Commercial glyceryl monostearate produced by acid-catalyzed glycerolysis of commercial stearic acid is eminently satisfactory. As compared to monoglyceridess produced by alkali-catalyzed glycerol cerolysis, such material is soap-free and, therefore, non-selfemulsifying.) Any organic compound which is a solid of semi-solid at ordinary temperatures, which melts at the reaction temperature to provide an oily liquid defining the medium in which the reaction is carried out in place of water, and which is of the high boiling, non-volatile type having solubility of dispersibility in water may be used. The plasticizer should be sufficiently hydrophilic to produce an emulsion when the final detergent cake product is used in water. The plasticizing agents that can be used should also be resistant to crystallization and segregation under the different temperature and aging conditions to which the detergent bar or cake may be subjected during storage and use. The plasticizing substances which are solid or semi-solid and which maintain a more or less definite form at ordinary temperatures are hereinafter referred to as normally solid substances.

Organic compounds which function satisfactorily as plasticizing agents and which broaden the plasticity range, as aforementioned, are the high molecular weight fatty acid esters of polyhydric alcohols. For example, long-chain polyhydric alcohol mono and distearates and particularly the ether-alcohol fatty acid esters, i.e., diethylene glycol monoand distearate are especially useful. These compounds are emulsifying agents, and promote the formation of a synthetic detergent bar having a smooth, uniform texture throughout. Other organic plasticizing agents which may be used are those normally solid glycerol monoesters of coconut fatty acids: ethylene glycol distearate, and the diethylene glycol mono and di-esters of palmitic myristic, oleic, lauric, and coconut oil acids as well as the corresponding hydrogenated fatty acids: propylene glycol mono and di-esters of stearic, oleic, lauric, myristic, palmitic, coconut oil fatty acids as well as suitable glyceryl and ethylene glycol mono esters of such fatty acids, and the like which esters are normally solid, and which dissolve in water but at a slow rate. Also suitable is a paraffin wax containing a polar compound which under the conditions of use of the bar will be sufficiently dispersed or emulsified. Mixtures of the various organic compounds may, of course, be employed. Where, however, substances are used which are readily dissolved in water, there is a tendency towards the production of a bar which is not as firm and dry to the touch as otherwise, and the finished bar or cake dissolves less slowly in water.

The water should be present during the sulfonation reaction in an amount from to by weight; 15% is the preferred amount, giving the highest yield. While an amount of water from 40 to 50% can also be used during sulfonation to give a relatively high yield, the viscosity of the mass is too high. The water must be added prior to the sulfonation reaction to lower the viscosity of the mixture during sulfonation. After sulfonation, the detergent mass is dried so that moisture is present in the final product in an amount of up to 10%, the upper limit being determined by the desired hardness of the detergent cake. The greater the quantity of moisture, the softer the bar.

A detergent bar, which contains a plasticity modifying agent as herein described, may gradually harden upon standing in the air at room temperature without charging its other physical properties or its chemical properties. It is preferred, however, to use a product such as glyceryl monostearate which is sufficiently hydrophilic to produce an emulsion when the final prod uct is dissolved in water. Preferably a glycerol monostearate derived from hydrogenated tallow oil is used, in which instance there is a substantial proportion of palmitic acid, rather than one which is derived from hydrogenated ground nut oil, which contains almost all stearic acid. In determining which plasticizer is to be used, a balance should be struck between hydrophilic and emollient properties. For example, it has been found that glyceryl monostearate is compatible with the production of an excellent foam and the complete absence of adherent scum, and leaves the hands with a dry and rather talc-like feel, while tallow alcohol leaves the hands with a slightly more emollient feeling. The tallow alcohol may be treated to form the ethylene oxide adduct thereof. Another desirable plasticizer that may be used in compatible amounts is the ethylene oxide adduct of hydrogenated tallow fatty acids.

The required proportion of plasticizer varies depending on the composition to be plodded and the plasticizing agent employed. The use of amounts of plasticizer of from about 5 to 60 percent by weight of the detergent mass may be utilized to advantage, and amounts of between 20 and 30 percent are highly desirable, with an amount of about 25 percent being preferred.

Chlorides were added to the mixture to extend the non-gelled range after sulfonation, primarily as a safety factor. The addition of chlorides up to 1% had differing effects, depending on the level of the water. At 5% and 10-15% water, chlorides increased the viscosity of the mass, at l520% water there was not substantial difference, and at 20-30% water chlorides decreased the viscosity in thefirst phase of cooling and reduced the gel ling. The chlorides tend to decrease slightly the yield of active ingredients because the sulfonation reaction is more violent and sulfur dioxide loss more evident.

An excess of sulfite of about 10 percentor more greatly increases the yield for formulas containing chlorides, reaching the maximum yields obtained. The viscosity of the mass is also increased with an excess of sulfite.

In addition to the essential ingredients set forth above, other toilet cake additives may be incorporated into the mass before it sets too hard and before it is shaped into its final bar form. Thus, inorganic or organic coloring materials, e.g., dyes, pigments, etc., may be utilized to give the plodded detergent cake or bar a pleasing color or tint. Some coloring materials such as titanium dioxide function both as a coloring agent and as a hardener. Glycerin may be incorporated to impart emollient characteristics to the finished bars or cakes and to enhance their gloss. Olive oil may also be used for this purpose and if desired, germicidal substances which are compatible and stable may be added. Other texture modifying ingredients such as lanolin, or aromatic additives such as perfume, may also be utilized.

In carrying out the formulation of detergent cakes in accordance with the procedure of this invention, the only equipment required is that which may be found in any commercial soap making operation. The process of this invention includes the step of admixing a higher molecular weight alcohol of the type described hereinabove with a bisor transbutenedioic acid or anhydride. The step involves the addition of the alcohol and anhydride or acid to a vat or kettle and the application of sufficient heat to melt the alcohol component and initiate the reaction which, being exothermic, continues of its own accord. During this reaction the temperature preferably is maintained below about C.. to minimize possible side reactions such as e.g., diesterification, Diels-Alder type reactions, and the like. The components of the reaction mixture will normally be used in quantities approximating their stoichiometric amounts. The butenedioic anhydride or acid is nor mally added to the vat after the alcohol component has been melted and the rate of addition thereof can be varied to maintain the reaction mixture at a predetermined temperature, preferably between about 55 and 65C. In the case of maleic anhydride, the temperature is easily controlled in this manner since the latent heat of fusion of the anhydride roughly balances the heat of reaction of the alcohol with the'anhydride. Following completion of substantial completion of this reaction, the mass is slowly heated to a temperature between about 90 and 105C. and the mass is maintained at this temperature for between 20 and 90 minutes to ensure completeness of the reaction.

After the reaction mass has been heated, the plasti I cizer, water and any sodium chloride used will advantageously be added with agitation until a clear liquid is formed. The temperature at this point should be about 4575C. For the sake of convenience, the mass should be held just above its solidification temperature. An appropriate sulfite, normally in finely divided form, is introduced into the vessel. During this step the mass is agitated and the temperature gradually raised to between about 90 and 100C.

As the sulfonation reaction proceeds, the viscosity of the reaction mass increases, the amount of increase of viscosity dependent on the quantity of water present. After the reaction has progressed for between 20 and 30 minutes, the viscosity of the mass may decrease.

The addition of sodium chloride helps to reduce any tendency to form a jelly structure and tends also to increase slightly the viscosity in the fluid phase. After a temperature of between 90 and 110C. is maintained for about 20 to 60 minutes, it may be desirable to add about one percent of hydrogen peroxide per 130 volumes of solution to oxidize any sulfur dioxide that may be present. When hydrogen peroxide is added, the mass is stirred for approximately another minutes. Any desired additives and adjuvants may be incorporated, and the product can then be passed to the ordinary dry ing and soap bar production apparatus, where it may be chilled on a chill roll, milled with or without additives such as perfume, etc., plodded, cut and stamped. The product formed by the process of this invention is of high quality, and the cake-forming steps are expedited because the composition does not stick to the stamping dies or other processing equipment.

In order to illustrate certain embodiments of the invention, the following examples are set forth. In the examples, and throughout the specification and claims, all parts are stated as parts by weight of the final product unless otherwise indicated.

EXAMPLE 1 Into a stainless steel reaction vessel fitted with a steam jacket, a gate type stirrer, and simple fume exhaust, there is charged 258 parts by weight of commer cial lauryl alcohol*, and this is heated to about 75C., at which temperature it is a free flowing oil. While stirring, there is added 121 parts of maleic anhydride granular solids at such a rate that the temperature remains at about 75C. The temperature is easily controlled by the rate of addition of the maleic anhydride, the latent heat of fusing the solid roughly balancing the heat of reaction of the alcohol and the anhydride. Commercial lauryl alcohol is the alcohol obtained by the catalytic hydrogenation of coconut oil or a fraction thereof from which the higher and lower homologues have been removed. Such a fraction may consist of C 20% CH. and 5% ofa mixture ofpredominantly C and C or it may be the corresponding similar product obtained by the Ziegler condensation of ethylene. or a C1243 fraction formed as a petroleum by product.

During this operation, fumes are exhausted to the atmosphere because a small amount of the anhydride evaporates.

After the addition of maleic anhydride is completed, mixing is continued for about 30 minutes, until the mass clears to a pale straw colored liquid. The tempe rature then increased to C., and 366 parts of neutral, commercial glyceryl monostearate** is added, and the whole mass stirred to a clear liquid. When the glyceryl monostearate is completely dissolved, 98.2 parts of water is added, and the temperature is descreased to about 75C.

** By commercial glyceryl monostearate is meant a glyceryl monostearate formed from commercial stearic acid.

Subsequently, 156 parts of powdered anhydrous sodium sulfite is introduced into the vessel. The mass is stirred and the temperature is gradually raised to 93C. Upon raising the temperature of the mass, the viscosity gradually increases very slightly. After the mass is heated to this temperature for 36 minutes, 10 parts of hydrogen peroxide per 130 volumes of solution is stirred in to oxidize any sulfur dioxide. After stirring for 10 minutes the mass is discharged into a drum drier or a chill roll to obtain sheets. The sheets are dried at room conditions to reduce the moisture content to about 5 percent. The sheets set to a hard, soap-like mass constituting an excellent base for a toilet cake.

An excellent product is obtained to which is added one percent each of a dye, and a perfume. The additives are incorporated after the mass sets, the mass is milled, and the cakes are then formed into a suitable shape and size by extruding, cutting and stamping. Control of the process is no more difficult than that of any soap manufacturing operation, and the constituents used are relatively inexpensive and commercially available. The product is benigh to the skin, rapidly forms a highly desirable quantity of foam, has a high detergent activity, and is completely free of adherent scum or curd.

EXAMPLE ll Into an enameled reaction vessel equipped with a stirrer having scraper blades, a steam jacket, and a simple fume exhaust, there is added 245 parts by weight of a commercial lauryl alcohol, and this is heated to 68C. Subsequently, parts of maleic anhydride is added and the temperature allowed to rise to 96C., which temperature is maintained for one half hour. During this time any fumes that are formed are exhausted to the atmosphere. There is then added 347 parts of glyceryl monostearate, and during such addition, the temperature drops to 60C. Water is then added in an amount of 146 parts by weight. Subsequently, 148 parts by weight of sodium sulfite is added. The exothermic reaction which ensues causes the temperature to rise to 94C., and the mass puffs up to approximately twice its volume (due to release of sulfur dioxide and steam). The temperature is then maintained between 87 and 94C. for about 1 hour, by which time the reaction is completed. Approximately two parts of 3% hydrogen peroxide solution is then added to scavenge any sulfur dioxide, and the mixture is stirred for 10 minutes, following which it is removed from the mixer and dried by means of a Procter-Schwartz forced convection apparatus.

EXAMPLES Ill-VI Representing the Following Water Content With respect to Examples lII-Vl, the most useful viscosity gradients through the sulfonation step was achieved'when the water content was about 19% by weight of the total material; see Example III and VI. Concomitantly, it was found that excellent active ingredient was produced. Even better viscosity results were obtained when a small quantity of a salt such as sodium chloride was included, as in Example 111.

It will be understood that various changes may be made by those skilled in the art without deviating from the principle and scope of the invention as expressed in the appended claims.

What is claimed is:

1. A process for the production of cleansing cakes comprising reacting approximately stoichrometric quantities of a butenedioic acid or anhydride and a compound having therein a reactive hydroxyl group and an acyclic chain at least predominately of 12 carbon atoms at a temperature between the melting point of said acid or anhydride and about 100C to produce a monoalkyl ester of butenedioic acid. reacting stoichiometirc quantities of said monoalkyl ester with a sulfite chosen from the group consisting of alkali metal, ammonium and alkaline earth metal sulfites and bisulfites in the presence of from 5 to 60% by weight of a molten plasticizer chosen from the group consisting of fatty acid esters of polyhydric alcohols and paraffin wax and mixtures thereof and from about 15 to 20% by weight of water at a temperature from about C to about C to form a water-soluble monoalkylsulfosuccinate, cooling the resulting product, drying the resulting product, and forming the cooled product into cakes, said cakes including at least about 40% of said monoalkylsulfosuccinate by weight.

2. The process of claim 1 in which the amount of water is 15%.

3. The process of claim 1 wherein the monoalkyl ester of a butenedioic acid is reacted with a sulfite in the presence of a molten plasticizer and up to 1% by weight sodium chloride.

4. The process of claim 1 wherein said sulfite is sodium sulfite.

5. The process of claim 1 wherein said plasticizer is glyceryl monostearate. 

1. A PROCESS FOR THE PRODUCTION OF CLEANINGS CAKES COMPRISING REACTING APPROXIMATELY STIOCHROMETRIC QUANTITIES OF A BUTENEDIOIC ACID OF ANHYDRIDE AND A COMPOUND HAVING THEREIN A REACTIVE HYDROXYL GROUP AND AN ACYCLIC CHAIN AT LEAST PREDOMINATELY OF 12 CARBON ATOMS AT A TEMPERATURE BETWEEN THE MELTING POINT OF SAID ACID OR ANHDRIDE AND ABOUT 100*C. TO PRODUCE A MONOALKYL ESTER OF BUTENEDIOC ACID, REACTING STOICHIOMETRIC QUANTITIES OF SAID MONOALKYL ESTER WITH A SULFITE CHOSEN FROM THE GROUP CONSISTING OF ALKALI METAL, AMMONIUM AND ALKALINE EARTH METAL SULFITES AND BISULFITES IN THE PRESENCE OF FROM 5 TO 60% BY WEIGHT OF A MOLTEN PLASTICIZER CHOSEN FROM THE GROUP CONSISTING OF FATTY ACID ESTES OF POLYHYDRIC ALCOHOLS AND PARAFFIN WAX AND MIXTURES THEREOF AND FROM ABOUT 15 TO 20% BY WEIGHT OF WATER AT A TEMPERATURE FROM ABOUT 90*C TO ABOUT 100*C. TO FORM A WATER-SOLUBLE MONALKYLSULFOSUCCINATE, COOLING THE RESULTING PRODUCT, DRYING THE RESULTING PRODUCT, AND FORMING THE COOLED PRODUCT INTO CAKES, SAID CAKES INCLUDING AT LEAST ABOUT 40% OF SAID MONOALKYLSULFOSUCCINATE BY WEIGHT.
 2. The process of claim 1 in which the amount of water is 15%.
 3. The process of claim 1 wherein the monoalkyl ester of a butenedioic acid is reacted with a sulfite in the presence of a molten plasticizer and up to 1% by weight sodium chloride.
 4. The process of claim 1 wherein said sulfite is sodium sulfite.
 5. The process of claim 1 wherein said plasticizer is glyceryl monostearate. 